Extensible mast structures for hydraulic towers



March 1958 H. J. TROCH ETAL 6,

EXTENSIBLE MAST STRUCTURES FOR HYDRAULIC TOWERS Original Filed Sept. 16, 1950 v 5 sheets shet 1 mmvroxs HERMANJ. TROCHEii jy JAMES l-%ARD HOLAN ULJ ATI'OR N EY March 11, 1958 H. J. TRC J CHE ETAL 1 2,826,280

EXTENSIBLE MAST STRUCTURES FOR HYDRAULIC TOWERS Original Filedsept. 16, 1950 5 Sheets-Sheet2 INVENTORS im E m O RD N J m T M MT A H A aw m M H J V.\ 3%

March-11, 1958 H. J. TROCHE ETAL 2,826,280

EXTENSIBLE MAST STRUCTURES FOR HYDRAULIC TOWERS Original- Filed Sept. 16, 1950 5Sheets-Sheet 5 IN V EN TORS ERMAN J. moan-1i BY 5 JAMES OfiRD H N ATTOR EY March 11, 1958 H. J. TROCHE ETAL 2,826,280

EXTENSIBLE MAST STRUCTURES FOR HYDRAULIC TOWERS Original Filed Sept. 16, 1950 5 Sheets-Sheeb 4 I INVENTORS 7| 70 HERMANJTROCHEfi Y M -L HOWARD HOLAN ATTORNEY March 11, 1958 H. J. TROCHE ETAL EXTENSIBLE MAST STRUCTURES FOR HYDRAULIC TOWERS 5 Sheets-Sheet 5 INVENTORS N J. moo-15 yJAMES HOWARD HOLAN Original Filed Sept. 16. 1950 United States Patent 0 EXTENsrnrn ass srnucrunns ron HYDRAULIC rownns Herman J. Troclie', Fairview Park, and James Howard Holan, Rocky River, Ohio, assignors to .l. H. Holan Corporation, Cleveland, Ohio, a corporation of @hio Original application September 16, 1950, Serial No. 185,268, now Patent No. 2,753,224, dated July 3, 1956. Divided and this application May 16, 1955, Serial No. 508,486

12 Claims. (Cl. 189-l4) The invention relates to hydraulic towers and particularly tomechanism of this character designed for heavy duty. More particularly, the invention relates to an improved extensible mast structure for hydraulic towers,

which is divided out of our pending application for Hydraulic Towers, now Patent No. 2,753,224. This extensible mast structure includes a plurality of telescoping units which can be extended to various selective working heights, and can be collapsed into a comparatively short height.

Although the hydraulic tower, of which said extensible mast structure constitutes a part, is designed for use on any suitable support, it is particularly designed for use with a utility truck body, and the invention in extensible mast structures is illustrated by a description herein and ashowing thereof in the accompanying drawing as applied to a utility truck chassis. An important use of utility truck bodies is practiced in the installation and maintenance of public utility facilities.

The instant improved mast structure is raised and lowered by hydraulic mechanism, its functions are electrically controlled, and the controls are hooked-up with the truck engine and battery.

Included amongst the objects and advantages of the invention in extensible mast structures herein presented are the following:

The mast structure is installed at a comparatively low initial investment, and is easly to install and maintain.

It consists of a comparatively small number of unit assemblies which are easily replaced. I

It is available in a number of servicing heights, for instance, total heights from about 17 feet to about 30 feet, and has a low collapsed height which provides ample clearance for underpasses and garage parking. It

is adaptable for use with working platforms of various types, such as stationary, rotary, and transversely movable, new and improved forms of which mentioned types of working platforms are shown and described in said Patent No. 2,753,224.

Various actuating mechanisms and controls are shown and described in said Patent No. 2,753,224, and will be herein referred to and shown to that extent necessary for a clear and definite understanding of the operation and control serving for the mast structure forming the subject matter of the instant application. It may be stated that a push-button control governs the hydraulic system and is so positioned as to eliminate the necessity of workmen bending over to operate it. There are multiple sets of electrical controls for convenient operation located at various points,- for instance, in the truck cab, on the truck body, and on the working platform which is supported on top of the extensible mast. These controls permit stopping of the extensible mast structure at any height, and an: emergency manual control is provided for use in the even of engine failure when the mast is extended.

The subject matter directed to the control systems for draulic cylinder.

operating the tower, and claims to such control systems, are presented in a pending divisional application Serial No. 508,485, filed May 16, 1955.

As shown and described in detail in said Patent No; 2,753,224, further actuating units and controls include an automatic engine speed regulator which eliminates the necessity of manual control from the cab for this purpose, this automatic speed regulator insuring proper mast and engine speeds at all times; also, an improved metering device which, without the necessity of manuallyactuated valves or control rods, insures an approximately constant mast-unit speed while raising and lowering the mast, and provides low maintenance cost. Any suitable mast speed can be provided as desired. Particular attention is directed to the convenience of the mounting of the mast structure on a utility truck, such mounting being within a minimum of truck space since the installation requires only about 14 inches, longitudinally measured, from the back of the truck cab to the rear end of the supporting channels for the mast.

The mast includes telescoping frame sections of the box type which provide a maximum of strength and stability, and within these frame sections are enclosed telescoping cylindrical mast units forming a floating hy These telescoping box type frame sec tions are provided with interior adjustable wear plates.

The mast structure is adaptable to various types of utility truck chassis, as hereinafter fully described.

The instant invention is directed to the above-memtioned structure with the attainment of the advantages mentioned and also certain related advantages which will be hereinafter fully described in detail and are shown in the accompanying drawings.

The mast will be hereinafter referred to as having" its front immediately to the rear of the truck cab, and the respective left and right sides of the mast will be thus referred to as if viewing the mast from the rear of the truck.

The annexed drawings and the following description set forth in detail certain means illustrating the improve ments in extensible mast structures, such means consti tuting, however, only a few of the various forms in which the principle of the invention may be embodied.

In said annexed drawings:

Figure l is a left side elevation of a hydraulic tower, of which the improved mast structure forms a part, mounted with a truck body upon the chassis of a utility truck, this figure showing the mast in lowered positionand also including an upper working platform which is of the stationary type;

Figure 2 is a rear elevation of the elements shown in Figure 1, the truck body being suggested by dot-anddash lines;

Figure 3 is a rear elevation of the improved mast structure in a raised position, a transversely-movable type of upper working platform in extreme moved position being also shown;

'Figures 4 and 5 together constitute a central transverse vertical section looking toward the front of the truck body, of the vertically-movable telescoping mast and frame units in lowered position, these figures being upon an enlarged scale and particularly illustrating the telescoping features of the mast;

Figure 6 is a top plan section of the telescoping mast and frame units, taken in the planes indicated by the line 6-6, Figure 4; and

Figure 7 is a diagrammatic showing of control units for actuating the vertical telescoping units of the mast.

Referring to the annexed drawings in which the same parts are designated by the same respective numbers in the several views, a cab 1 and a body 2 of a utility truck asaazso v Q are shown in Figures 1 and 2, upon the chassis 14 of which the improved tower forming the subject matter of said Patent No. 2,753,224 is mounted, a part of this tower being the improved extensible mast structure forming the subject matter of the instant application. A part of the tower structure shown in Figures 1 and 2 includes a fixed working platform 6 supported by a base 15 secured to the mast structure and the working platform.

igure 3 shows the mast 4 and the surrounding frame 5 in elevated position and mounted upon a different type of chassis 14 carrying a utility truck body 2. Furthermore, the mast structure shown in Figure 3 has a platform 7 of the transversely-movable type which is shown in its extended position.

The mast structure can be mounted upon the longitudinal side channels 3 of the chassis 14 or 14, Figures 1, 2, 3, and 6; Figure 3 indicating one way in which the height of the mounting can be adjusted so as to meet the conditions presented by various types of chassis.

The vertically extensible mast structure comprises, broadly, a plurality of telescoping cylinders constituting an inner mast or floating hydraulic chamber designated by the general number 4, and a plurality of reinforced telescoping two-part side channels constituting an outer frame designated by the general number 5. These mast and frame units are combined with a fixed horizontal platform designated by the general number 6, such as is illustrated in Figures 1 and 2, or a transversely-movable platform designated by the general number 7, such as is illustrated in Figure 3. Other types of upper working platforms may be combined with the improved mast structure as a part of the complete tower, such as the rotary type of platform shown and described in said Patent No. 2,753,224.

The operating and control assembly comprises a hydraulic system designated by the general number 9, Figures 3, 5, 6, and 7, including an oil tank 10, Figures 2, 3, 5, and 6, on the right side of the tower base, and a pump 11 at the front, Figures 5 and 6; also an electrical assembly designated by the general number 12, Figure 7, such electrical assembly 12 including a control housing 13, Figures 2, 3, 5, and 6, on the left side of the tower base. There are various electrical switch stations, such as station 16 on the platform 7, Figure 3. Further switch stations, not shown, are available in the cab 1 and on the body 2.

Referring particularly to Figures 1, 2, 3, 5, and 6, front and rear transverse tower base channels 21 are provided which are secured directly to the top of the longitudinal chassis channels 3, as shown in Figure 2, or, to accommodate various types of chassis, are secured thereto by depending angles 23, Figure 3, whose flanges are bolted to the cross channels 21, whose webs are bolted to the longitudinal chassis channels 3, and whose bottom ends are secured to the chassis 14. The angles 23 are of a length and design according with the type of chassis upon which the tower is mounted. The bottom of the tower is located about fourteen to fifteen inches from the ground and the tower cross channels 21 are mounted on the longitudinal channels 3 of the respective chassis so as to provide about this height for the bottom of the tower. Tank bracing angles 22, Figure 6, are welded to the tank and bolted to the cross channels 21. On the left side of the tower a channel 26 is welded to the control housing 13 which housing is mounted on the cross channels 21 and secured to the truck frame, Figure 6, or the control housing 13 may be otherwise suitably secured. A front cross channel 25, Figures 5 and 6, is welded to the longitudinal chassis channels 3 and supports the pump 11. Referring particularly to Figure 3, gussets 29 are welded to the bases of the webs of the respective outer channel units of the telescoping frame 5 and to the top of the cross channels 21.

Other base connecting and strengthening members are utilized as are required by the size and type of mast structure and type of chassis.

The working floor 74 of the transversely-movable platform 7, Figure 3, and the fixed platform 6, Figure l, are mounted upon front and rear transverse channels and longitudinal channels carried by the tubular trunnion 50, Figure 4, the detailed structure of which platforms 7 and 6 are fully shown and described in said Tower Patent No. 2,75 3,224; as also, the railings for said working platforms and the operation of the movable platform 7, but which structures and operation constitute no part of the invention claimed in the instant application.

The mast 4 includes five telescoping cylindrical vertical units, Figures 4, 5, 6, designated respectively, reading from the outside toward the inside of the mast 4-, by the numbers 31, 32, 33, 34, and 35, which five units make up a floating hydraulic cylinder. The outer mast unit 31 is stationary and has a base plate 36 secured by a bottom mast ring 37 which is bolted to and above front and rear extensions 36 of the base plate 36, Figure 6, and welded to the exterior surface of the outer cylinder 31. The base plate extensions 36 are secured by bolts 39 adjacent their front and rear ends to the tower cross channels 21. An oil seal ring 38 adjacently surrounds the bot tom of the outer mast unit 31 and is embedded in and at the bottom of the ring 37.

Adjacent the lower ends of the cylinders 31, 32, 33, 34, and 35, and between each adjacent two cylinders, are bearings 40, Figure 5, providing for the sliding of the four inner cylinders upon the respectively adjacently exterior cylinders. Adjacently above and below the bearings 44 are several series of stop rings which will now be mentioned. Exteriorly extending from each of the four inner cylinders and seated in the respective cylinders adjacently above the bearings 40 are an external type of split stop rings 43. Adjacently below the bearings 40 are also similarly positioned another like series of an external type of split stop rings 42. Adjacently below this last-mentioned series of stop rings 42 are a series of three internal type of split stop rings 41 which are seated in the three cylinders 32, 33, and 34 and extend inwardly of the respective cylinders. These internal stop rings 41 cooperate with the external stop rings 42 in the lowering of the tower. Materially above the rings 43 is a series of an external type of split stop rings 44 projected outwardly from the four inner cylinders 32, 33, 34, and 35. These rings 44 serve with the stufiing boxes 54 in raising the tower. Fluid relief holes 45 are drilled through the four inner cylinders 32, 33, 34, and 35 above the top series of stop rings 44.

The function and operation of the several series of stop rings will be hereinafter fully described.

A sloping cap 49, Figure 4, for the interior cylinder 35 is welded thereto and has a depending portion 49 securely engaging by its periphery the inner wall of the inner cylinder 35. A bolt and nut combination 51 also secures the cap 49 to the top of the inner cylinder 35, the bolt being an integral part of the sloping cap 49, and the nut being secured down upon a main front to rear tubular trunnion upon which the working platform for the tower is mounted.

Adequate sliding and sealing surfaces between each adjacent two of the telescoping mast units are provided adjacent the tops of the respective units 31, 32, 33, 34, and 35 by bearings 53, packing gland nuts and bearings 52, stufling boxes 54 welded to the tops of the four outer units 31, 32, 33, and 34, and wiper rings 55.

Slung from the cap 49 at the top of the inner cylinder 35 is the main rear to front horizontal tubular trunnion 50 to the top exterior surface of which is welded a cross box-like structure having side channel formations 89 to the webs of which are bolted angles 88 having lower flanges engaging the bottoms of the channel formations 89. These angles 88 and channels 89 are also bolted to the webs of vertical support channels 76 welded to the flanges of the units forming an inner frame member 63. There are four of these frame members which will be hereinafter fully described. The main longitudinal trununion 50 is also welded to transverse short tubes 86, Figure 4, which tubes 86 are also welded to the Webs of the channels 89, the tubes 86 being also bolted to the angles 88, the channels 76, and the channels 89.

The frame channel unit pairs are four in number, Figures 4, 5, and 6, and they have a foot plate 70 formed with side extensions 71 to which are bolted overlying front to rear horizontal plates 72 lying adjacently exteriorly of the webs of the outer stationary frame units 60 and welded thereto.

The opposed pairs of frame channel units 60, 61, 62, and 63 are secured together by crosswise corrugated strengthening members 75, Figures 1, 2, 3, 4, and 6, which are welded at their ends to the outer faces of the flanges of the respective pairs of opposed units 60, 61, 62, and 63. There are a plurality of spaced sets of these corrugated strengthening members 75 throughout the height of the frame, as clearly appears in Figures 1, 2, 3, and 4.

Interposed between the webs of the respectively adjacent pairs of telescoping frame units 60, 61, 62, and 63, and secured to the webs of the inner unit of each pair of units, at the top of the frame, are wear plates 81, Figures 4 and 6. There are like wear plates 80 at the bottom of the frame secured to the inner frame unit of the respectively adjacent pairs of frame units, Figure 5.

Corresponding wear plates 84, at the top of the frame, and wear plates 83 at the bottom of the frame, are interposed between the flanges of the respectively adjacent pairs of telescoping frame units and secured to the flanges of the inner units of the respective pairs.

External stop plates 82, at the bottom of the frame, are secured by welds 91 to the webs of the inner units of the respectively adjacent pairs of telescoping frame units 60, 61, 62, and 63; and, adjacent the top of the frame, there are interposed internal stop plates 85 secured by welds 92 to the webs of the outer of the respectively adjacent pairs of frame units.

The function and operation of the stop plates 82 and 85 will be hereinafter fully described.

Preliminary steps and operations initially essential to place the apparatus in condition for elevating the mast 4 and the frame 5 will be hereinafter fully described. Assuming these necessary initial steps have been taken, the hydraulically-operated tower is raised and lowered as follows:

By means and in a manner hereinafter fully described, oil is caused to flow through the port 20 in the base plate 36 of the mast 4, Figure 5, and the oil pressure effects the upward movement of the inner four mast cylinders 32, 33, 34, and 35 which, Figures 4 and 5, carry the inner frame unit 63 upwardly with them. When the upper external ring 44 on the mast unit 32 engages the bottom of the stufiing box 54 welded to the outer fixed mast unit 31, the upward movement of the mast unit 32 ceases. Thus, the mast member 32 then becomes stationary but the mast units 33, 34, and 35 continue moving upwardly. At this time the lower external stop plate 82 secured to the inner frame unit 63 is below the upper internal stop plate 85 secured to the frame unit 62. When the lower external stop plate 82 secured to the inner frame unit 63 engages the upper internal stop plate 85 secured to the frame unit 62, the frame unit 63 carries the frame unit 62 upwardly with it. The upward movement of the mast members 33, 34, and 35 carrying with them the frame members 62 and 63 continues until the upper stop ring 44 secured externally of the mast unit 33 engages the stuffing box 54 of the now stationary mast unit 32, at which time the upward movement of the mast unit 33 is stopped. At this time the lower external stop plate 82 on the frame unit 62 is below the upper internal'stop plate on the frame unit 61. Thus, the mast units 31, 32, and 33 will now be stationary, and the mast units 34 and 35 will continue upwardly carrying with them the frame units 61 and 62. When the lower external stop plate 82 on the frame unit 62 engages the upper internal stop plate 85 on the frame unit 61, the latter unit is carried upwardly with the units 62 and 63.

When the upper stop ring 44 secured externally to the mast unit 34 engages the stuffing box 54 welded to the mast unit 33, the upward movement of the mast member 34 is stopped and, thereafter, only the inner mast unit 35 continues upwardly carrying with it the frame units 61, 62, and 63. This upward movement of the inner mast unit 35 and frame units 61, 62, and 63 continues until the upper stop ring 44 secured externally of the mast unit 35 engages the stuffing box 54 welded to the mast unit 34. At this time the lower external stop plate 32 secured to the frame member 61 isadjacently below the upper internal stop plate 85 secured to the fixed frame member 60. When the tower is completely erected, all of the frame units are suspended from the mast assembly; for instance, frame unit 62 hangs from frame unit 63 and frame unit 61 hangs from frame unit 62.

When it is desired to lower the mast 4 and the frame 5, by means hereinafter fully described, oil flows from the interior of the mast through the port 20 and the lowering of the inner mast unit 35 commences and with it all of the frame units 61, 62, and 63. The lowering of the mast unit 35 as a single member continues until the external stop ring 42 secured adjacent the lower end thereof encounters the internal stop ring 41 secured to the mast unit 34. The engagement of said external stop ring 42 and said internal stop ring 41 causes the mast unit 34 to descend with the mast unit 35. Also, the lowering of all the frame units continues until the outer movable frame unit 61 comes to rest on the fixed support 70, but the two inner frame units 62 and 63 continue to descend. This sequence of operations is repeated, the external stop rings 42 and the internal stop rings 41 successively picking up additional mast units, and the frame members successively coming to rest upon the base 70 until the four inner mast units 32, 33, 34, and 35 settle together upon the base 36, and the innermost frame unit 63 comes to rest upon the base 70, Figures 4 and 5.

As hereinafter fully explained, it is not necessary that the upward extension of the tower mast and frame units be a maximum, such as has been described, but the upward extension may be stopped at any point either mechanically or by opening a switch (not shown) of the electrical assembly 12, Figure 7, as hereinafter described.

The action whereby the mast 4 and the frame 5 are vertically extended and lowered is hydraulic, and the path of oil for effecting this action is particularly shown in Figures 5, 6, and 7. This oil path comprises an outlet 1.3 from the bottom of the tank 10 through a sediment bulb casing 19, thence to the pump 11, thence to a control valve E, thence to a metering valve F, and thence through loop 372 to the interior of the mast 4 through the mast inlet 20. The return of the oil is from the mast 4 through the metering valve F by way of the loop 372, and thence to the control valve E and back to the tank inlet 24. This oil flow effects the raising and lowering of the mast 4 and the frame 5 and is obtained by the use of. some other detailed structure which will be referred to hereinafter. No actual oil pressure is required, however, to lower the mast 4 and the frame 5, these structures coming downwardly by their own weight when the path or flow of oil is properly set, as hereinafter fully described.

The metering valve F, Figures 6 and 7, is located between the control valve E and: the masts and frame 5 and determines the flow of oil according to the height of the frame 5. This metering valve F has a casing 232 formed with ports 233 and 234 with which an oil line 230 from and to the oil control valve E, and an oil line 231 to and from the mast 4, respectively communicate. Within the casing 232 is a valve 235. The stem 236 of the valve 235 is engaged at its outer end by a lever 237 which is pivotally mounted intermediate its ends in a block 238 mounted on the casing 232. One end of the lever 237, on the side of the pivotal mounting where the valve stem 236 is engaged, tends to move downwardly toward the casing 232 under the influence of a spring 239 secured at its top to the outer end of the lever 237 and secured at its bottom to a bracket 305 secured to the casing 232. A stop plate 275 erected on the valve casing 232 determines the extreme downward movement of the lever 237 by means of a screw 245 adjustably mounted on the lever 237. The inner end of the lever 237 intersects the frame units 61, 62, and 63 and is formed with an end angle plate 237 Figure 6, through which extend adjusting screws 307 and 308 which at their head ends can abut stops 240 and 241 secured respectively to the frame units 61 and 62. When the head of the adjusting screw 337 abuts the stop 249, a maximum flow of oil into the mast 4 results. The adjusting screw is set to produce the desired maximum flow and this continues as long as only the frame unit 63 is moving upwardly. When the head of the adjusting screw 3% abuts the stop 241, then a lesser amount of oil flow results. This occurs when the frame unit 62 moves upwardly carrying the adjusting screw 30'? with it. It will be understood that the tension of the spring 239 holds the inner end of the angle plate 237 upwardly in such position that the head of the screw 3% will abut the stop 241 if the position of the frame unit 62 so permits. The amount of move ment of the adjusting screw 398 in varying the oil flow from the maximum to the intermediate flow is indicated by the distance by which the head of the screw 308, Figure 6, is spaced from the stop 241. It will be understood that when the head of either of the screws 387 or 398 is abutting its stop 2% or 241; to control oil flow, the frame member upon which the controlling screw is mounted is not then moving upwardly so that the abutting position of the head of the screw against its stop determines the oil flow and preserves it constant until the frame member has moved upwardly and the next amount of oil flow commences to function. The adjusting screw 245 is so set that the minimum flow of oil results when the screw 245 contacts the stop plate 275. This minimum flow of oil is effective when all of the frame units 61, 62, and 63 are moving upwardly and are carrying with them the adjusting screws 307 and 308.

Secured to and adjacent the top of the stationary frame member 60 is a cutout switch 243. This switch functions when the adjacent frame unit 61 has reached its maximum height by reason of a contact 244 secured exteriorly of and adjacent the bottom end of this adjacent frame member 61, an engagement of the contact 244 with the cutout switch 243 cutting off the flow of oil into the mast 4 by electrical control, thus stopping the whole operation.

Referring to the diagrammatic showing in Figure 7, an oil line (not shown) leads from the outlet 18 of the tank to an inlet port (not shown) of an oil control valve E. The control valve E is comprised of a plurality of units and in said Patent No. 2,753,224 has four units one of which is a gathering unit leading from the valve E back to the inlet port 24 of the oil tank 10. This valve E also controls the flow of oil to and from a cylinder actuating the transverse movements of a transverselymovable platform 7 shown in Figure 3, all as fully described and claimed in said Patent No. 2,753,224. Var ious elements of an electrical control assembly 12, including solenoids and vacuum cylinders (not shown, but all fully shown and described in said Patent No. 2,753,224), actuate structures of the control valve E for feeding the lil all)

oil to and from the mast 4 and to and from the cylinder for the transversely-movable platform 7. There is a regulator H for these movements (not shown) but which is fully shown and described in said Patent No. 2,753,224. This regulator H is connected to the throttle of the engine carburetor by a wire 262 and accelerates in both directions of movement, all as fully shown and described in said Patent No. 2,75 3,224. As a part of this control there is also a vacuum line 252 extending from a vacuum pump 333 and communicating with the solenoids. An oil line 239 communicates at its respective ends with a port (not shown) from one of the units of the control valve E and a port 233 in the casing 232 of the metering valve 1 An oil line 231 communicates with a port 234 in the casing 232 of the metering valve F and the port 2% in mast communicating with the interior of the mast below the mast units.

The mast cylinders 32, 33, 34, and 35 are started in their upward travel by the closing of a switch in the electrical system 12. Such switch closing opens the vacuum line to a chamber of a solenoid casing.

Likewise, the starting of the downward movement of the mast cylinders 32, 33, 34, and 35 is effected by closing another switch of the electrical system 12 and thus opening another portion of the solenoid chamber to vacuum. The equipment for these controls and the functioning of this equipment are all fully shown and described in said Patent No. 2,753,224.

What we claim is:

1. In a tower, an extensible mast structure, a support therefor, the mast comprising telescoping members, one of the mast members being stationary relative to the support, means for moving the other mast members upward- 1y as a unit, cooperative means on adjacent mast members stopping the upward movement of said other mast members in succession, a frame, a support upon which the frame is based, the frame being slung from a movable mast member and comprising telescoping members of which one member is stationary relative to the frame support, and cooperative means on adjacent relatively movable frame members initiating the upward movement of the movable frame members in succession, whereby eventually all the movable frame members move upwardly as a unit.

2. In a tower, characterized as in claim 1, in which the cooperative means for moving the frame members upwardly in succession are pickup plates secured to respectively adjacent frame members, and the frame is slung from the mast member last stopped in its upward movement.

3. In a tower, characterized as in claim 1, in which the number of telescoping mast members is one more than the number of telescoping frame members.

4. In a tower, characterized as in claim 1, in which the frame is slung from the inner mast member, in which the inner mast member is the last mast member whose upward movement is stopped, and in which the successive stopping of the upward movement of the movable mast members alternates with the initiating of the upward movement of the movable frame members.

5. In a tower, characterized as in claim 1, in which the cooperative means for stopping the upward movement of the other mast members in succession are stop rings on the respective inner mast members and stuffing boxes on the respectively outer mast members.

6. In a tower, characterized as in claim 1, in which the cooperative means for moving the frame members upwardly in succession are pick-up plates secured to and respectively adjacent relatively movable frame members. in which the cooperative means for stopping the upward movement of the other mast members in succession are stop rings on the respective inner mast members and stuffing boxes on the respectively outer mast members, and in which the frame is slung from the innermost mast member.

7. In a tower, characterized as in claim 1, in which the telescoping mast members are tubular.

8. In a tower, characterized as in claim 1, in which the telescoping mast members are tubular, and in which each frame member comprises opposed connected channel members surrounding the mast members.

9. In a tower, characterized as in claim 1, in which the frame members comprise opposed channel units, in which the respective channel units of each frame member are secured together, in which a trunnion is intersected by the upper end of the mast structure, and in which reinforcing channel members are secured to the trunnion and to the respective channel units of the inner frame member.

10. In a tower, an extensible mast structure, a support therefor, the mast comprising telescoping members, the outer one of the mast members being stationary relative to the support, external rings secured to each of the movable mast members, stuffing boxes engaging the respective rings and mounted on the respectively outer mast members of each adjacent pair of mast members, means for moving the movable mast members upwardly as a unit, the external rings and stutfing boxes stopping the upward movement of the mast members in succession commencing with the outermost movable mast member, a trunnion intersected by the upper end of the mast structure, a frame, a support upon which the frame is based, the frame comprising telescoping members of which the outer member is stationary relative to the frame support, channel members secured to the trunnion and to the inner frame member, lower stop plates secured externally of each movable frame member, upper stop plates secured internally of the outer frame member of the respective pairs of adjacent frame members and adapted to 10 be engaged by the respective lower stop plates whereby the movable frame members are picked up in sequence and finally all movable frame members move upwardly as a unit.

11. In a tower, characterized as in claim 1, in which are provided cooperative means on adjacent mast members effecting successive lowering engagement of movable mast members during a tower-lowering operation, whereby all of the movable mast members settle together on the mast support, and in which the cooperative means on the adjacent frame members permit settling of the movable frame members in succession on the frame support.

12. In a tower, characterized as in claim 10, in which the means for moving the telescoping mast members is a hydraulic system, in which there is a second series of external rings secured to the movable mast members below the aforesaid external rings, in which there is a series of internal rings secured to movable mast members below said second series of external rings, in which, upon the withdrawal of the hydraulic moving medium, and the consequent lowering of the mast and frame, rings of said References Cited in the file of this patent UNITED STATES PATENTS Crippen Mar. 11, 1890 McPherson Sept. 21, 1909 

